Radiographic bone-age assessment is widely used as a tool in clinical practice and for research studies. With the traditional atlas-based method, a trained reader performs bone-age scoring by viewing a juvenile hand radiograph on a back-illuminated viewing box. The reader systematically compares regions of interest (ROI's) on the radiograph to images and written descriptions in an atlas that represent different stages of bone growth. For each ROI, the reader assigns a score for the stage that best matches the atlas. Atlas-based bone-age assessment suffers from several difficulties and inconveniences that can increase the time and cost of the readings and that compromise the precision and accuracy of the method. The possibility of recording errors also exists since the reader must enter the scores to a data sheet by hand. We propose to develop a computer graphical user interface (GUI) tool to perform Tanner-Whitehouse (TW2) bone-age assessment. The images and written description from the Tanner atlas will be put into a computer database and displayed on the monitor along with the digitized hand radiograph to be evaluated. The GUI tool will have image adjustment tools and software will be developed to create automatically the ROI's for the evaluation image. Once the reader is satisfied with a score, it can be automatically put into a scoring database and retrieved for analysis at a later time. This system will be more convenient and less costly than the traditional TW2 scoring and we also hypothesize that the precision will be improved. Since it will be developed for the Windows operating system, it can be made widely available to other researchers and clinicians.